By the time Donald J. Trump is sitting at his federal trial on charges of criminally conspiring to overturn the 2020 election, he may have already secured enough delegates to effectively clinch the Republican Party’s 2024 presidential nomination.

The former president’s trial is scheduled to start March 4, by which point five states are expected to have held nominating contests. The next day, March 5, is Super Tuesday, when 15 states, including delegate-rich California and Texas, plan to hold votes that will determine if any Trump challenger has enough political oxygen to remain a viable alternative.

Primaries in Florida, Ohio and Illinois come two weeks later. Florida and Ohio will be the first winner-take-all contests, in which the top vote-getter statewide seizes all of the delegates rather than splitting them proportionally. Winner-take-all primaries have historically turbocharged the front-runner’s path to the presidential nomination. Mr. Trump’s federal trial, if it proceeds on its current timeline, won’t be close to finished by then.

The collision course between the Republican Party’s calendar and Mr. Trump’s trial schedule is emblematic of one of the most unusual nominating contests in American history. It is a Trump-dominated clash that will define not only the course of the 2024 presidential primary but potentially the future direction of the party in an eventual post-Trump era.

“It’s a front-runner set of rules now,” said Clayton Henson, who manages the ballot access and delegate selection process for the Trump campaign, which has been instrumental in rewriting the rules to benefit him.

Mr. Trump has complained the March 4 start date of the trial amounts to “election interference” and cited Super Tuesday, but it is likely to have a greater effect on his ability to campaign for primaries in subsequent weeks. About 60 percent of the delegates will be awarded from contests after Super Tuesday.

Generally, defendants are required to be present in the courtroom at their trials. After preliminary matters such as jury selection, prosecutors in Mr. Trump’s election case have estimated they will need about four to six weeks to present their case, after which defense lawyers will have an opportunity to call additional witnesses.

That timeline also means it is likely that a majority of the delegates will have been awarded before a jury determines Mr. Trump’s fate.

If Mr. Trump holds his dominant polling advantage throughout the primaries but then a jury transforms him into a convicted felon, any forces within the G.O.P. that would want to use that development to stop him would have one last opportunity to block his nomination — the same end-run around voters that officials tried at the party convention in 2016.

That possibility would almost certainly lead to a schism between Trump loyalists and what used to be called the party’s establishment, an unpleasant reality in which defeating Mr. Trump could doom Republicans to a long cycle of electoral defeats.

“Given what’s happening on the legal front, state parties need to think about what options they’re giving themselves” to allow delegates flexibility at the party’s national convention, said Bill Palatucci, a Republican National Committee member from New Jersey who advises the super PAC supporting Chris Christie and who opposes Mr. Trump.

Republican state parties have until Oct. 1 to submit their formal delegate allocation rules to the national committee.

“All this is happening so quickly, it’s unprecedented, and so as states formulate what their rules are going to be,” Mr. Palatucci added, “everybody’s got a whole new set of circumstances to consider.”

There are no signs that the party’s leadership is contemplating using Mr. Trump’s legal troubles against him. The chairwoman of the R.N.C., Ronna McDaniel, has defended Mr. Trump in numerous media appearances and the committee has been raising money by telling online donors that the former president is the victim of a political prosecution.

On Monday night, just hours after Judge Tanya S. Chutkan set the March trial date, one of the main organs of the Republican establishment, The Wall Street Journal’s editorial page, sounded the alarm.

“Mr. Trump might have the G.O.P. nomination sewn up before a verdict arrives and voters learn whether he’s a convicted felon,” the Journal editors wrote. “This would certainly delight Democrats.”

The renewed panic about the possibility of nominating a convicted felon recalls the 2016 effort to block Mr. Trump’s nomination after he had won a clear delegate majority in the primaries.

Then, a group of Republican delegates loyal to Senator Ted Cruz of Texas tried to muster support from one-fourth of the convention’s rules committee, a body that meets in the weeks before the national convention, to throw open the nominating contest to the full roster of more than 2,000 delegates. Had they succeeded, the renegade delegates still would have needed a majority vote of all the delegates in order to seize the nomination from Mr. Trump.

Now, short of a full capitulation from Mr. Trump, removing him as the nominee at the convention after he has secured enough delegates remains an extreme long shot. A surrender by Mr. Trump seems highly unlikely given that advisers have said he views getting re-elected — and taking command of the pardon power plus control over the Justice Department — as his best insurance policy. Despite Mr. Trump’s claims, however, it is not clear that a president can pardon himself, so he might be on safer legal ground if some other Republican secured the nomination, became president and then pardoned him.

The Trump campaign is taking no chances on a contested convention. His team is far more experienced and professional than it was in 2016, when Mr. Cruz’s forces organized state party conventions in Louisiana, Colorado and elsewhere to elect Cruz loyalists as convention rules committee delegates. Mr. Trump has a tighter grip on the party’s grass-roots supporters than he did in 2016, and his aides — including Mr. Henson, Brian Jack, Susie Wiles and Chris LaCivita — have been working for months behind the scenes to ensure he will have loyal delegates in state parties across the country, according to people with direct knowledge of their efforts.

Mr. Trump’s team also has a stronger hold on state parties themselves, after three advisers — Bill Stepien, Justin Clark and Nick Trainer — worked to consolidate support within them ahead of the 2020 election to stave off primary challenges to Mr. Trump. Many of those changes, which favor Mr. Trump, remain in place.

Mr. Trump himself has gotten involved deep in the weeds of convention politics. He has awarded endorsements not just for state party bosses but for leaders of the two largest county Republican parties in Nevada — the sort of local officials who will have significant influence in choosing which grass-roots leaders will represent their states as convention delegates next July in Milwaukee.

This loyalty has already delivered results for Mr. Trump’s campaign. This month, the Nevada Republican Party quietly announced it would not share political data or coordinate with super PACs — a blow to Gov. Ron DeSantis of Florida, who has outsourced much of his campaign’s political operation to the super PAC Never Back Down. Never Back Down is led by Jeff Roe, the architect of Mr. Cruz’s 2016 campaign.

Mr. LaCivita said in a statement that “no degree of trickery or gamesmanship” and “no amount of editorials in The Wall Street Journal” would stop Mr. Trump’s nomination at the convention.

“There’s been much more attention to detail and focus on those small things,” he added, “that if not attended to early on can lead to big headaches.”

The mere possibility of a chaotic contested national political convention — a dream of political observers who have known nothing but scripted, made-for-television quadrennial gatherings since 1980 — may inspire well-funded Trump rivals to remain in the race just in case delegates decide it would be foolhardy to anoint a convicted felon as their party’s standard-bearer for the general election.

Mr. Trump has vowed to appeal the March 4 trial date in the election case. That is not legally permitted: Generally, grievances over issues like whether a defense team had adequate time to prepare must wait to be taken up on appeal after any guilty verdict.

Still, it is possible that his legal team will ask an appeals court or the Supreme Court to intervene before the trial using a long-shot method known as a petition for a writ of mandamus. Higher courts tend to be reluctant to grant such requests to disrupt the normal judicial process and have set a very high bar that must be met before they will consider doing so.

Even if a jury acquits Mr. Trump in the federal election case — or one or more holdout jurors produce a mistrial — there are three other cases that could potentially lead to him being a convicted criminal by the time of the convention.

He is facing bookkeeping fraud charges in New York, where a trial is set to begin March 25, although it is now might be pushed back. He is set to go on trial in Florida in May on federal charges related to his hoarding of sensitive national-security documents after leaving office. And he has been charged in another 2020 election case in Georgia, for which a trial date has not yet been set.

Ben Ginsberg, who for decades was among the Republican Party’s top election lawyers before breaking with the party over Mr. Trump in 2020, said no amount of delegate machinations would be likely to stop a Trump nomination should he win enough early nominating contests.

“If he wins Iowa and New Hampshire,” Mr. Ginsberg said, “I think it’s all over anyway.”